Phys.org February 15, 2024 A team of researchers in the US (US Naval Research Laboratory, Kansas State University) demonstrated how hexagonal boron nitride (hBN) slabs tuned to the correct thickness act as optical waveguides, enabling direct optical coupling of light emission from encapsulated layers into waveguide modes. They integrated molybdenum selenide (MoSe2) and tungsten selenide (WSe2) within hBN-based waveguides and demonstrated direct coupling of photoluminescence emitted by in-plane and out-of-plane transition dipoles (bright and dark excitons) to slab waveguide modes. They demonstrated that dry etched hBN edges are an effective out-coupler of waveguided light without the need for oil-immersion optics. […]
Tag Archives: Layered materials
Merons and antimerons
Science Daily April 11, 2023 Out-of-plane polar domain structures have recently been discovered in strained and twisted bilayers of inversion symmetry broken systems such as hexagonal boron nitride. An international team of researchers (Belgium, UK, USA – Harvard University) has shown that this symmetry breaking also gives rise to an in-plane component of polarization, and the form of the total polarization is determined purely from symmetry considerations. The in-plane component of the polarization makes the polar domains in strained and twisted bilayers topologically non-trivial, forming a network of merons and antimerons (half-skyrmions and half-antiskyrmions). For twisted systems, the merons are […]